1. Field of the Invention
This invention relates to the field of mass storage systems. In particular, the invention relates to the management of storage transactions in, and the configuration of, intelligent storage area networks.
2. Description of the Related Art
The storage of large amounts of data in so-called mass storage systems is becoming a common practice. Mass storage systems typically include storage devices coupled to file servers on data networks. Users in the network communicate with the file servers for access to the data. The file servers are typically connected to specific storage devices via data channels. The data channels are usually implemented with point-to-point communication protocols designed for managing storage transactions.
As the amount of storage increases, and the number of file servers in communication networks grows, the concept of a storage area network (SAN) has arisen. Storage area networks connect a number of mass storage systems in a communication network which is optimized for storage transactions. For example, fibre channel arbitrated loop (FC-AL) networks are being implemented as SANs. The SANs support many point-to-point communication sessions between users of the storage systems and the specific storage systems on the SAN.
File servers and other users of the storage systems are configured to communicate with specific storage media. As the storage systems expand or media is replaced in the system, reconfiguration is required at the file servers and other users. Also, if a need arises to move the data from one device to another, in a so-called data migration operation, it is often necessary to block access to the data during the migration process. After migration is complete, reconfiguration at the user system must be executed to make the data available from the new device.
Overall, as the complexity and size of storage systems and networks increase, the problems of managing configuration of the users of the data and of the storage systems themselves multiply. Accordingly, there is a need for systems that simplify management of storage systems, while taking advantage of the flexibility and power of the SAN architecture.
The present invention provides systems and methods for storage domain management. Storage domain management is a centralized and secure management capability that layers on top of existing storage area network hardware infrastructures to provide high-performance, high availability and advanced storage management functionality for heterogeneous environments. Storage domain management provides a core of a robust storage area network fabric that can integrate legacy and new equipment, off-load network and storage management tasks from the servers and storage resources, and host network-based applications so that they can be leveraged across all components of the storage area network. Storage domain management allows for the creation and optimization of a heterogeneous storage area network environment not available using prior art systems and techniques.
The present invention provides a system for managing storage resources in a storage network according to storage domains. The system includes a plurality of communication interfaces, adapted for connection via communication media to clients and storage systems and the storage network. A processing unit is coupled with the plurality of communication interfaces and includes logic to configure a set of storage locations from the one or more storage systems in the network as a storage domain for a set of at least one client from the one or more clients in the storage network. The system includes in various combinations elements providing multi-protocol support across the plurality of communication interfaces, logic to route storage transactions within a storage domain in response to the transaction identifiers carried within the protocols, a management interface for configuring the storage domains, logic for translating a storage transaction traversing the plurality of communication interfaces into and out of a common format for routing within the system among the plurality of communication interfaces, resources for caching the data subject of storage transactions, and logic to manage the migration of data sets from one storage location to another storage location within the network.
In one embodiment, the system according to the present invention is included as an intermediate device in a storage area network, between client processors, such as file servers, and storage systems used as storage resources in a storage domain for the clients. Storage transactions are received by the intermediate device, and managed according to the configuration of the storage domain defined by configuration logic in the intermediate device. The intermediate device provides a management site within a storage area network that allows for flexible configuration, redundancy, failover, data migration, caching, and support of multiple protocols. Furthermore, an intermediate device in one embodiment provides emulation of legacy systems, allowing the storage domain to include a legacy storage device for the client without a requirement for reconfiguration of the client.
Storage domains are managed by assigning a logical storage extent to clients within the network, and by mapping storage resources in the network to the logical storage extents of the clients. The assignment of logical storage extents to clients is accomplished by the mapping in an intermediate system, or other system logically independent of, or isolated from, the client of storage resources in the network to the logical storage extent assigned to the client. In this manner, a storage domain of storage resources accessible via a storage domain manager is managed using the storage domain manager as the intermediate device.
In a preferred embodiment, the resources within storage domains are defined using virtual circuits which comprise a plurality of driver modules and configurable logic linking driver modules into data paths, which are implemented in pairs for redundancy in a preferred system. Each configured data path acts as a virtual circuit that includes a set of driver modules selected from the plurality of driver modules. A data storage transaction which is received at a communication interface is mapped to one of the configured data paths, and thereby controlled within a storage domain managed and configured in the storage domain manager.
Fundamentally, storage domain management enables customers to realize the full promise of storage area networks to address business problems. The storage domain management platform provides for heterogeneous interoperability of storage systems and protocols, provides for secure centralized management, provides for scalability and high performance, and provides for reliability, availability and serviceability features, all on an intelligent, purpose-built platform.
Other aspects and advantages of the present invention can be seen on review of the figures, the detailed description and the claims which follow.